Collapsible scaffold



Dec. 2, 1947.

F. HARTMANN COLLAPSIBLE SCAFFOLD 2 Sheets-Sheet 1 Filed Feb. 25, 1946FIGII.

1, III- FlG.7.

. INVENTOR I 5 FRED HARTMANN' BY M1 0 9 4 6 a Q 5 2 2 U 4 2 a 9 i i Q l!u m z W I! r M M m 5 W m ATTORNEY F. HARTMANN I GOLLAPSIBLE SCAFFOLDFiled Feb. 25, 1946 g Sheets-Sheet 2 FIGA, k

FIG.3.

INVENTOR:

ATTORNEY FRED HARTMANN Patented Dec. 2, 1947 UNITED STATES PATENT OFFICE2,431,933 COLLAPSIBLE scAFroL-n' Fred Hartmann, St. Louis, Mo.Application February 25, 1946 Serial No. 649,997

1 Claim. 1

My invention has relation to improvements in collapsible scafiolds andit consists in the novel features of construction more fully set forthin the specification and pointed out in the claim.

The present invention is an improving departure over that shown in mycopending application Serial No. 620,907, filed October 8, 1945, in thatit is a simpler structure although having the same general objects inview.

The principal object of the invention is to provide a scaffold that maybe erected by one workman, and when knocked down, may be packed in acomparatively narrow space for shipment.

A further object is to provide a scaffold that may be adjusted to anylength within its compass, a plurality of widths, and any height up toits maximum. All these adjustments may be effected by a single workman.These objects as well as other advantages embodied in the construction,will be better apparent from a detailed description of the invention inconnection with the accompanying drawings, in which- Figure 1 is an endelevation of one of the supporting frames extended to its maximum width;Fig. 2 is an enlarged cross-section through one of the standards takenon the line 2-2 of Fig. 1; Fig. 3 is a side elevation of one of thesupporting frames showing a part of the rail which carries the scaffoldplatform; Fig. 4 is an enlarged crosssection taken on line 44 of Fig. 1looking at the opposite side of the standard to that shown in Fig. 3;Fig. 5 is a cross-sectional detail taken on the line 55 of Fig. 3; Fig.6 is an enlarged crosssectional detail taken on the line 6--6 of Fig 3and Fig. '7 is a cross-sectional detail taken on the line 'I-'! of Fig.4.

Referring to the drawings, F represents one of the end frames (of whichthere are two of identical construction) comprising standards I, Iadjustably connected by cross-braces 2, 2' and a brace-bar 3, the latterbeing pivotally fixed to brace 2 and adjustably connected to brace 2' bya stud 4, adapted to pass through any one of a series of holes 5, 5,etc., evenly spaced for adjusting the space between standards I, I. Awing-nut E secures the braces 2, 2 and bar 3 firmly in place.

The lower ends of braces 2, 2' are secured to studs 1, l projecting fromthe standards I, I by wing-nuts 8, 8, while the upper ends of the bracesare adjustably secured to slotted channels 9, 9 fixed by welding (orotherwise) to the outer faces of standards I, I. In order that thebraces 2, 2 may be secured in any position along the slots [0, l0,handle clamps II, II are screwed over studs I2, I2 traversing the slots(Fig. 2).

In order to assist the workman in erecting the end frames F, each of thestandards I is braced by a triangular leg frame comprising inclined legmembers 13, 13' pivotally connected adjacent to their upper .endsby alooserivet I4 (or equivalent) and diverge downwardly, being held insupporting position by braces I5, I5. One of the legs l3 has anextension I6 which is perforated to fit over a stud I'I projecting fromthe outer side face of the standard I, and a wing-nut I8 holds the upperpart of the leg frame in place. The inner ends of braces l5, I5 aremounted on a stud I9 projecting from the standard I, near the bottomthereof, and are secured by a wing-nut 2|], while the outer ends of thebraces I5, I5 are secured to the legs I3, I3 by studs 2| and wing-nuts22.

The standards I, l are substantially U-shaped, each having slots 23bounded by inwardly turned flanges a, a, said slots being on their innerside faces against which slide bars 24, 24 are clamped. Within eachstandard I is a channel bar 25 coextensive with slide bar 24, theflanges b, b of said channel bar bearing against the inside surface ofthe standard On each side of the flanges a, a, and a plurality of studs26 traverse the slot 23 and pass through openings 21 in the slide bar24. Wing-nuts 28 are screwed over the studs to hold the slide bar firmlyagainst the standard I. Near the lower end of bar 24 is a perforatedboss 29 in which is rotatably mounted a U-shaped hanger 30 which fitsinto any one of a number of evenly spaced notches 3| formed in flange ofa notch bar 32.

The hanger 30 serves to assist the wing-nuts 28 in holding the slide bar24 in place and also supports the slide bar when the wing-nuts areloosened for the purpose of efiecting adjustment of the slide bar.

The slide bar 24 has a rectangular frame 33 formed near its upper end toreceive one end of rail 34 (of which there is one On each side). Therails support the platform 35.

In order to brace the scaffold against longitudinal slippage, eachstandard I is provided with a longitudinal brace member 36, the outerend of which has a series of holes 31, any one of which may be passedover a stud 38 projecting from lug 39 on the outer side wall of thestandard and securely held by a wing-nut 4|]. The inner end of member 36has a stirrup 4I pivotally connected to it and a pair of thumb screws42, 42 traverse the stirrup to engage the rail 34 over which the stirrupis passed. Frame 33 is also traversed by thumb screws 43, 43 forengagement with rail 34.

When the scafiold is to be collapsed for storage or shipment, the rails34. 34 and platform 35 are removed, after which brace-bar 3 isdisconnected from brace 2 and handle clamps II, II loosened. The workmanmay now bring the standards I, l at each end into juxtaposition andagain tighten the handle clamps II, II to hold the standards together.The next operation in compacting the scafiold is to remove wing nut l8and loosen wing nuts 29 and 22, so the le frame comprising legs l3, I3may be folded up as shown (dot and dash lines, Fig. 3) and leg member I3secured over stud 44 above stud ll.

Obviously after rails 34 and platform 35 are removed the brace member 36is also disconnected from standard I.

When the scaffold is to be set up so the platform 35 is only a shortdistance above the floor, the slide bars 24 may be inverted so the frame33 will be at the lower end of the slide bar instead of at the upperend. When this done the braces 36 are also inverted and are secured attheir outer ends to studs 45 projecting from the top of channels 9.

Having described my invention, I claim:

A scaffold having collapsible end frames, said frames includingsupporting standards, hangers slidingly mounted on said standards, meansfor anchoring the hangers thereto, slotted members fixed to thestandards, cross-braces operating in said slotted members to effectlateral adjustment of the standards, means for locking the crossbracesin a plurality of positions, and a collapsible leg frame fixed to eachstandard to form a tripod therewith.

FRED HARTMANN.

REFERENCES CITED The following references are of record in the file ofthis patent:

